Circuit/System Testing
WARNING: This page is about a different car, the 2010 GMC Sierra and 2010 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- Verify that DTCs P018B, P018C, P018D, P0231, P0232, or P023F are not set.
- If the DTCs are set, refer to DTC P018B-P018D or DTC P0231, P0232, or P023F .
- Ignition OFF, disconnect the harness connector at the fuel tank pump module.
- Ignition ON, test for less than 5.0 ohms between the fuel pump module low reference circuit terminal A and ground.
- If greater than the specified range, test the fuel pump module low reference circuit for a high resistance. If the circuit tests normal, replace the fuel pump control module.
- Ignition OFF, install a test lamp between the control circuit terminal D and the control circuit terminal A.
- Ignition ON, command the fuel pump ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
- If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the fuel pump control module.
- If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the fuel pump control module.
- If all circuits test normal, perform the Fuel System Diagnosis to verify proper fuel pressure.